Domestic passengers using Heathrow rose by 4.4% last month with the introduction of new Flybe flights to Scotland.
The total number using UK flights increased to 397,000 in March over the same month last year as the regional carrier introduced flights to Aberdeen and Edinburgh after Heathrow cut domestic passenger charges by a third.
Overall passenger volumes were up by almost 5% in March, when adjusted for different Easter timings, with a record 6.16 million using the London hub. This was driven by growth to East Asia (up 8%), Latin America (up 7%) and the Middle East (up 6%) in addition to strong domestic numbers.
The rolling annual total of passengers using Heathrow to the end of March edged up by 0.9% to more than 76 million, representing 472,295 aircraft movements.
Heathrow CEO John Holland-Kaye said: “Surging trade, more domestic connections and more long-haul growth are the bedrock of the UK’s economy.
“Today’s figures put Britain in a strong position as the government begins Brexit negotiations and underline the unique role Heathrow plays as the nation’s global gateway.
“Our expansion plans will give Britain the tools to do even better. We’ll double our domestic connections and add up to 40 new long-haul trading links, making the UK the best connected country on earth.
“It’s a huge prize that only Heathrow delivers and we’re getting on with securing it for Britain.”